I also suggest no time limit on treaty amendment votes.
So, I suggest the following.
Voting Regulations
a. A vote is open for a maximum of 7 days.
b. If a vote reaches 50%+1 of all members in favor before the end of 7 days it passes.
c. If a vote reaches 50%+1 of at least 1/2 of all members by the end of 7 days it passes.
d. If these two conditions are not met, the vote fails.
e. Treaty Amendments have no time limit.